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101.
Geoffrey Dixon 《International Journal of Theoretical Physics》1975,12(3):153-156
The authors empirically based contention that there exists an integral mass system for the principal baryons and the electron is put into a theoretical framework. This framework predicts a neutrally charged lepton which must correspond to the neutrino, generates very accurate base masses for the major leptons, mesons, and baryons and extremely accurate mass splitting for the principal octet of baryons. In addition, it predicts a totally new class of super heavy particles the lightest of which would have a mass greater than 38 GeV. 相似文献
102.
103.
Dr. J. M. Dixon 《Zeitschrift für Physik B Condensed Matter》1972,15(3):237-246
A study is made of two useful perturbation schemes describing theE
g orbitals of a paramagnetic ion coupled very strongly to a cluster surrounding a cubically symmetric lattice site in the harmonic
approximation. The two methods correspond to the cases when the vibrational states have low and large angular momentum. The
limitations of both approaches are discussed and the zero order eigenvalues and eigenfunctions are given in each case. 相似文献
104.
105.
R. K. Walter J. C. Hopkins E. C. Kerr J. T. Martin A. Niiler J. D. Seagrave R. H. Sherman D. R. Dixon 《Physics letters. [Part B]》1969,30(9):626-627
The asymmetries from
elastic scattering of 22.1 MeV incident neutrons was measured for 11 laboratory angles between 40° and 118.5°. The extrema are −60% at 85° (lab) and +98% at 110° (lab). 相似文献
106.
Geoffrey Dixon 《Letters in Mathematical Physics》1981,5(5):411-418
The concept of the Clifford algebra of a bilinear form defined on a vector space, is generalized to include both orthogonal and symplectic forms. This new characterization is intimately tied to a particular anti-automorphism defined on the algebras which in the orthogonal case, provides a unified approach to the reversion and principle anti-involutions of an ordinary Clifford algebra. Most attention is concentrated on the physically important symplectic Clifford algebras, including the link between these and Lie superalgebras.Until February, 1982 at the Institüt für Theoretische Physik, Universität Karlsruhe, 75 Karlsruhe 1, Kaiserstr. 12, W. Germany. 相似文献
107.
Shumate WJ Mattern DL Jaiswal A Dixon DA White TR Burgess J Honciuc A Metzger RM 《The journal of physical chemistry. B》2006,110(23):11146-11159
We report spectroscopic characterization and unimolecular rectification (asymmetric electrical conduction) measurements of three donor-sigma-acceptor (D-sigma-A) compounds N-(10-nonadecyl)-N-(1-pyrenylmethyl)perylene-3,4,9,10-bis(dicarboximide) (1), N-(10-nonadecyl)-N-(4-[1-pyrenyl]butyl)perylene-3,4,9,10-bis(dicarboximide) (2), and N-(10-nonadecyl)-N-(2-ferrocenylethyl)perylene-3,4,9,10-bis(dicarboximide) (3). These molecules were arranged as one-molecule thick Langmuir-Blodgett monolayers between Au electrodes. In such an "Au | D-sigma-A | Au" sandwich, molecule 1 is a unimolecular rectifier, with rather small rectification ratios (between 2 and 3 at +/-1 V) that decrease upon cycling. Molecule 2 does not rectify. Molecule 3 rectifies, with a rectification ratio of between 14 and 28 at +/-1 V; the through-film rectification and currents persist, even with scans of +/-2 V, for up to 40 cycles of measurement. Qualitative arguments, based on a two-level rectification mechanism, are consistent with the current asymmetries observed in the monolayers of 1 and 3. 相似文献
108.
To understand the structural factors that control the adsorption of acid dyes onto cotton (cellulose), the adsorption of 15 acid dyes from water has been studied. An equilibrium exists between dye adsorbed in the cotton and dye in solution, and by measurement of the temperature dependence (277-333K) of the equilibrium constant, the enthalpy and entropy of binding are obtained. For most dyes adsorption is driven by the binding enthalpy, which is ascribed to van der Waals forces. Acid dyes consist of an aromatic core with peripheral solubilizing groups (generally sulfonates). Dyes in which the sulfonates are on one side of the molecule have the largest binding enthalpy. Assuming a binding geometry where the sulfonates protrude into water pools in the bulk amorphous regions and as much as possible of the dye core touches the surface, then a good correlation exists between the binding enthalpy and the summation of 1/r(6) over all the C, N, and O dye atoms, where r is the distance of each atom from the cellulose surface. 相似文献
109.
A highly enantioselective Mannich reaction between malonate esters and N-Boc and N-Cbz aldimines, catalysed by a bifunctional cinchonine derivative, has been developed; extension of this methodology to encompass the use of 2-substituted-1,3-dicarbonyl nucleophiles allows the formation of adjacent stereocentres, one of which is quaternary, in high relative and absolute stereocontrol. 相似文献
110.
Coupled-cluster calculations through noniterative triple excitations were used to compute optimized structures, atomization energies at 0 K, and heats of formation at 0 and 298 K for NH2O, HNOH, NH2O-, NH2OH+, NH3OH+, HNO-, and HON. These molecules are important in the gas-phase oxidation of NH3, as well as its solution-phase chemistry. The O-H, N-H, and N-O bond energies of these molecules are given and compared. The N-H and O-H bond energies are quite low, and, for NH2OH, the O-H bond is weaker than the N-H bond (by 7.5 kcal/mol). The energetics for a variety of ionic chemical processes in the gas phase, including the electron affinities of NH2O and HNO, the proton affinities of NH2O and NH2OH, and the acidities of NH2OH and NH2O, are given. The compounds are weak bases and weak acids in the gas phase. Solvation effects were included at the PCM and COSMO levels. The COSMO model gave better values than the PCM model. The relative values for pKa for NH2O and NH2OH are in good agreement with the experimental values, showing both compounds to be very strong bases in aqueous solution with NH2OH being the stronger base by 1.8 pK units at the COSMO level, compared to the experimental pK difference of 1.1+/-0.3 pK units. We predict that NH2OH+ will not be formed in aqueous solution, because it is a very strong acid. Based on the known acidity of NH3OH+, we predict pKa(NH2OH+)=-5.4 at the COSMO level, which is in good agreement with the experimental estimate of pKa(NH2OH+)=-7+/-2. 相似文献